Android Instant Messaging / Chat XMPP不在手机上接收消息

Question

嗨，我正在开始android开发，并试图做一个即时通讯/聊天应用程序。 我在这里下载了此源代码，并试图了解其工作原理。 我的问题是在2台移动设备上，其中1个用户无法收到另一用户的消息，反之亦然，但是我可以在gmail帐户上看到这些聊天消息。 并且，如果我从gmail帐户浏览器中键入了一条消息，则使用移动设备的用户收到了该消息（这使我认为问题出在“ connection.sendPacket（msg）;”中）。

public class XMPPChatDemoActivity extends Activity {

    public static final String HOST = "talk.google.com";
    public static final int PORT = 5222;
    public static final String SERVICE = "gmail.com";
    public static final String USERNAME = "xxxxxxxx@gmail.com";
    public static final String PASSWORD = "xxxxxxx";

    private XMPPConnection connection;
    private ArrayList<String> messages = new ArrayList<String>();
    private Handler mHandler = new Handler();

    private EditText recipient;
    private EditText textMessage;
    private ListView listview;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        recipient = (EditText) this.findViewById(R.id.toET);
        textMessage = (EditText) this.findViewById(R.id.chatET);
        listview = (ListView) this.findViewById(R.id.listMessages);
        setListAdapter();

        // Set a listener to send a chat text message
        Button send = (Button) this.findViewById(R.id.sendBtn);
        send.setOnClickListener(new View.OnClickListener() {
            public void onClick(View view) {
                String to = recipient.getText().toString();
                String text = textMessage.getText().toString();

                Message msg = new Message(to, Message.Type.groupchat);
                msg.setBody(text);              
                if (connection != null) {
                    connection.sendPacket(msg);
                    messages.add(connection.getUser() + ":");
                    messages.add(text);
                    setListAdapter();
                }
            }
        });

        connect();
    }

    /**
     * Called by Settings dialog when a connection is establised with the XMPP
     * server
     * 
     * @param connection
     */
    public void setConnection(XMPPConnection connection) {
        this.connection = connection;
        if (connection != null) {
            // Add a packet listener to get messages sent to us
            PacketFilter filter = new MessageTypeFilter(Message.Type.chat);
            connection.addPacketListener(new PacketListener() {
                @Override
                public void processPacket(Packet packet) {
                    Message message = (Message) packet;
                    if (message.getBody() != null) {
                        String fromName = StringUtils.parseBareAddress(message.getFrom());
                        messages.add(fromName + ":");
                        messages.add(message.getBody());
                        // Add the incoming message to the list view
                        mHandler.post(new Runnable() {
                            public void run() {
                                setListAdapter();
                            }
                        });
                    }
                }
            }, filter);
        }
    }

    private void setListAdapter() {
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
                R.layout.listitem, messages);
        listview.setAdapter(adapter);
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        try {
            if (connection != null)
                connection.disconnect();
        } catch (Exception e) {

        }
    }

    public void connect() {

        final ProgressDialog dialog = ProgressDialog.show(this,
                "Connecting...", "Please wait...", false);

        Thread t = new Thread(new Runnable() {

            @Override
            public void run() {
                // Create a connection
                ConnectionConfiguration connConfig = new ConnectionConfiguration(
                        HOST, PORT, SERVICE);
                XMPPConnection connection = new XMPPConnection(connConfig);

                try {
                    connection.connect();
                    Log.i("XMPPChatDemoActivity",
                            "Connected to " + connection.getHost());
                } catch (XMPPException ex) {
                    Log.e("XMPPChatDemoActivity", "Failed to connect to "
                            + connection.getHost());
                    Log.e("XMPPChatDemoActivity", ex.toString());
                    setConnection(null);
                }
                try {
                    // SASLAuthentication.supportSASLMechanism("PLAIN", 0);
                    connection.login(USERNAME, PASSWORD);
                    Log.i("XMPPChatDemoActivity",
                            "Logged in as " + connection.getUser());

                    // Set the status to available
                    Presence presence = new Presence(Presence.Type.available);
                    connection.sendPacket(presence);
                    setConnection(connection);

                    Roster roster = connection.getRoster();
                    Collection<RosterEntry> entries = roster.getEntries();
                    for (RosterEntry entry : entries) {
                        Log.d("XMPPChatDemoActivity",
                                "--------------------------------------");
                        Log.d("XMPPChatDemoActivity", "RosterEntry " + entry);
                        Log.d("XMPPChatDemoActivity",
                                "User: " + entry.getUser());
                        Log.d("XMPPChatDemoActivity",
                                "Name: " + entry.getName());
                        Log.d("XMPPChatDemoActivity",
                                "Status: " + entry.getStatus());
                        Log.d("XMPPChatDemoActivity",
                                "Type: " + entry.getType());
                        Presence entryPresence = roster.getPresence(entry
                                .getUser());

                        Log.d("XMPPChatDemoActivity", "Presence Status: "
                                + entryPresence.getStatus());
                        Log.d("XMPPChatDemoActivity", "Presence Type: "
                                + entryPresence.getType());
                        Presence.Type type = entryPresence.getType();
                        if (type == Presence.Type.available)
                            Log.d("XMPPChatDemoActivity", "Presence AVIALABLE");
                        Log.d("XMPPChatDemoActivity", "Presence : "
                                + entryPresence);

                    }
                } catch (XMPPException ex) {
                    Log.e("XMPPChatDemoActivity", "Failed to log in as "
                            + USERNAME);
                    Log.e("XMPPChatDemoActivity", ex.toString());
                    setConnection(null);
                }

                dialog.dismiss();
            }
        });
        t.start();
        dialog.show();
    }
}

非常感谢你。